Computer equipment is continually evolving to operate at higher power levels. Increasing power levels pose challenges with regard to heat management. For example, many data centers now employ individual racks of blade servers that can develop 20,000 watts, or more, worth of thermal load. To accommodate the greater thermal loads resulting from higher power levels, conventional data center cooling systems inevitably must also operate at higher power levels in order to provide the amount of necessary cooling. As a result, the overall energy budget for the data center (including, for example, power for information technology (IT) equipment and data center infrastructure, such as lights, coupled with the power for the cooling system) can increase exponentially.
With a steady rise in energy costs, much research effort is directed to coming up with more energy-efficient alternatives. Some recent efforts have focused on improving data center cooling efficiency. For example, data centers commonly employ a raised floor cooling system, wherein space between a raised floor and a sub-floor, i.e., a sub-floor plenum, serves as a conduit to transport cooled air from air conditioning units (ACUs) to IT equipment racks in the data center. Techniques have been proposed for more efficiently arranging the IT racks to maximize the effect of available cooling.
Other more energy-efficient alternatives, however, would be greatly desirable, especially as cooling requirements continue to increase and currently available capabilities are exceeded.